Disabling the built in security alarm? (passlock)

danpat · January 13, 2004

I have a 2000 Silverado 2500 ext. Sometime I start it and it runs great... sometime I start it and it shuts back off. I can the crank it until the battery is dead but it will not fire. I checked the the fuel pressure reg. and it seems to be ok. I stuck my head under the rear wheel well and I can hear the fuel pump building pressure before I start it. If I wait awhile and try it again sometimes it will start or it may not and i have to wait longer. Then maybe next time it will. Twice now when it did the security light came on so now I am leaning tword the passlock system giving me this headacke. I should also mention that it has a remote starter on it that has never given me a problem. If it is the starter, how would I check it the passlock was being bypassed? I am not ready to blame the auto started yet because it does this whether I use the key or not.

All that and my question is that, is there a way to disable the factor alarm? Either a fuse or one of the computer tricks? (like pressing the gas pedal 3 times while flashing the high beams and hopping on one leg) I'll also take any other advice that could be given on this.

Thanks,

Dan

karld · January 14, 2004

Don't know if this will be much help,but the passlock sensor in my truck failed which in turn turned on the security light steady. When this happened it went into a failsafe mode which allowed me to start the truck.

Jeremy WI · January 14, 2004

I think I heard about problems with some ignition switches that caused this problem, you could take it to a dealer and see what it would cost or complain about it enough they will either fix it cheap or kick you out

toddgotfish · January 14, 2004

when your remote starter was installed a passlock bypass

module was also installed (555L)if a wire from this unit came off

or the unit went bad then this is def you problem.

these units sell on ebay for less than 30.00 .

buut if the install is less than a year old its probably still under

waranty( take it back and havem check it out)

remember the 555L was not part of your remote start system .

it is a seperate piece that MUST be used to remote start and therefore

supplied by the alarm installer

99-2door · January 15, 2004

when your remote starter was installed a passlock bypass
module was also installed (555L)if a wire from this unit came off

or the unit went bad then this is def you problem.

these units sell on ebay for less than 30.00 .

buut if the install is less than a year old its probably still under

waranty( take it back and havem check it out)

remember the 555L was not part of your remote start system .

it is a seperate piece that MUST be used to remote start and therefore

supplied by the alarm installer

Either that or your installer cheaped out on you and permenently by-passed your PASSLOCK with a few wires and a resistor. If something is making a intermittant connection it could cause your problem.

danpat · January 15, 2004

Thanks guys, I am going to get under the dash this weekend and take a look, weather permitting. Yep. I bought a truck that will not fit in my garage and the snow is coming down today.

I bought the truck with the starter already installed. The dealer gave me the remotes and told me he didn't know what they were for. It was a nice surprise when I make the right button sequence (by luck) and the truck started. I've been using it ever since.

I tried to start the truck yesterday morning, thinking it might be ok if I do not set the alarm, but it started and shut right back off. I went home last night and tried again and it started right up. I used to move the camper in the yard. Again that security light was on. Once it starts it is 100% ok though.

I'm going to check that bypass, then it is off to the scan tool if necessary. I found a local guy that has one.

GMINSIDE · January 16, 2004

the way the passlock system works is if the ressistance in the circuit is not sense within a certin amout of time it will shut the fuel pump down and the only way to get it to restart is to have someone reset it with a scan tool.i dont know if it can be done withe just any tool though.the passlock system is hidden in the bcm so it has to be accced throu that.